Rontó Györgyi, Bérces Attila, Lammer Helmut, Cockell Charles S, Molina-Cuberos Gregorio J, Patel Manish R, Selsis Franck
MTA-SE Research Group for Biophysics, Semmelweis University, Budapest, Hungary.
Photochem Photobiol. 2003 Jan;77(1):34-40. doi: 10.1562/0031-8655(2003)077<0034:suicot>2.0.co;2.
The UV radiation environment on planetary surfaces and within atmospheres is of importance in a wide range of scientific disciplines. Solar UV radiation is a driving force of chemical and organic evolution and serves also as a constraint in biological evolution. In this work we modeled the transmission of present and early solar UV radiation from 200 to 400 nm through the present-day and early (3.5 Gyr ago) Martian atmosphere for a variety of possible cases, including dust loading, observed and modeled O3 concentrations. The UV stress on microorganisms and/or molecules essential for life was estimated by using DNA damaging effects (specifically bacteriophage T7 killing and uracil dimerization) for various irradiation conditions on the present and ancient Martian surface. Our study suggests that the UV irradiance on the early Martian surface 3.5 Gyr ago may have been comparable with that of present-day Earth, and though the current Martian UV environment is still quite severe from a biological viewpoint, we show that substantial protection can still be afforded under dust and ice.
行星表面和大气层内的紫外线辐射环境在广泛的科学学科中都具有重要意义。太阳紫外线辐射是化学和有机演化的驱动力，同时也是生物演化的一个限制因素。在这项工作中，我们针对包括尘埃负荷、观测到的和模拟的臭氧浓度等各种可能情况，对现今和早期（35亿年前）太阳紫外线辐射从200至400纳米透过现今和早期火星大气层的传输情况进行了建模。通过利用DNA损伤效应（特别是噬菌体T7杀灭和尿嘧啶二聚化），针对现今和古代火星表面的各种辐照条件，估算了对微生物和/或生命必需分子的紫外线应激。我们的研究表明，35亿年前早期火星表面的紫外线辐照度可能与现今地球的相当，并且尽管从生物学角度来看当前火星的紫外线环境仍然相当严峻，但我们表明在尘埃和冰层之下仍能提供实质性的保护。
